주요우울증 환자에서의 청각 사건관련 전위 P300

Auditory Event-related Potential P300 in Patients with Major Depression

Event-related potential (ERP) has been demonstrated to be sensitive to both sensory and cognitive processes. P300 component of the ERP is regarded as an endogenous evoked potential which can be altered by psychological or cognitive differences. In this study, we investigated the characteristics of amplitude and latency of P300 using two tone discrimination task in 22 patients with major depression compared to those of 14 control subjects. We obtained the following results. 1) The latencies of P300 were prolonged in depressed group than control subjects with statistical significance( p < 0 .0 5 ). 2) Although there is no statistical significance, the latencies of P300 showed more prolonged trend according to the severity of the depressive symptoms(r= 0.393). 3) the latencies of P300 were markedly prolonged in the group that showed more severe depressive symptoms than those with less severe symptoms(p〈0.005). This findings suggests that the latencies and ampitudes of P300 may be useful clinical measures which can reflect cognitive dysfunction in patients with major depression